1. Field of the Invention
The present invention relates to electro-optical systems for reading indicia of different light reflectivity, such as bar code symbols. In particular, the present invention to a handheld data entry terminal of improved ergonomic design.
2. Description of Related Prior Art
Related to the handheld data entry terminal of the present invention are the laser scanner systems and components disclosed in U.S. Pat. Nos. 4,387,297; 4,460,120; 4,816,661; 4,806,742; and 4,845,350, as well as U.S. patent applications Ser. Nos. 07/148,669, 07/147,708 and 08/061,070. All of these patents and patent applications are owned by the assignee of the present invention and are incorporated herein by reference.
As exemplified in the cited related art, a light source, such as a laser, generates a light beam which is directed by optical components along a light path toward a bar code symbol. The laser light beam is repetitively scanned by a scanning component, such as an oscillating mirror situated in the beam path, to sweep a beam spot beam across the bar code symbol. A photodetector detects light of variable intensity reflected or scattered from the symbol and generates electrical signals indicative of the detected light. These electrical signals are decoded and into data representative of the data encoded in the symbol.
Barcode scanner terminals are basically of two types, the fixed installation type exemplified by the scanners incorporated in supermarket checkout counters and the portable type. The portable type is particularly advantageous in situations where articles bearing the barcode symbols cannot, from a practical standpoint, be brought to a fixed scanner terminal to enter the barcode data. Thus, for example, handheld barcode scanners are particularly advantageous to inventory stock distributed throughout a store, warehouse, etc.
Known handheld barcode scanners have taken a variety of shapes. A pistol shape has been a popular configuration due to the inherent ease in aiming the laser beam at a target barcode symbol. Unfortunately, a pistol-shaped scanner is not particularly conducive to the inclusion of other desirable features, such as a data entry keypad and an output device, such as a liquid crystal display (LCD). Also, it is very difficult to design an ergonomic, portable barcode scanner and keypad data entry terminal that is convenient to use by both left and right-handed operators.